Precipitation of metal proteinates from brines by base-acid-base hydrolysis

ABSTRACT

An improved method for the production of metal proteinates from an aqueous slurry of a proteinaceous precipitating reagent and a mineral source material such as a natural or synthetic brine, and/or from a reaction of dry salts mixed directly with a proteinaceous precipitating reagent known as the moist paste method, and wherein the precipitating reagent, in both cases is made by the base-acid-base hydrolysis of a protein-containing substance.

United States Patent 1191 Richards, Jr.

" Nov. 27, 1973 PRECIPITATION OF METAL PROTEINATES FROM BRINES BYBASE-AClD-BASE HYDROLYSIS Inventor: Albert Z. Richards, Jr., Salt LakeCity, Utah Assignee: Key Minerals Corporation, Salt Lake City, UtahFiled: Jan. 8, 1971 Appl. No.: 105,087

I Related US. Application Data Continuation-impart of Ser. No. 787,147,Dec. 26, 1968, abandoned.

US. Cl. 426/364, 71/23, 260/534 R 1111. c1. A23k 1/175, C05f 11/00 Fieldof Search 99/2, 7, 17, 18; 210/50, 53, 54'; 71/11, 21, 23, 25; 23/298,300; 260/534 R References Cited UNITED STATES PATENTS 11/1952 Pacau 99/7X 17H CONTWOL REAGENT 3,050,383 8/1962 Wilson 71/1 1 3,374,081 3/1968Miller 71/11 3,396,104 8/1968 Miller 71/23 3,574,592 Hartung 71/23 XPrimary Examiner-Norman Yudkoff Assistant Examiner-Kenneth P. Van WyckAttorney-Clarence A. OBrien and Harvey B.

Jacobson [57] 1 ABSTRACT An improved method for the production of metalproteinates from an aqueous slurry of a proteinaceous precipitatingreagent and a mineral source material such as a natural or syntheticbrine, and/or from a reaction of dry salts mixed directly with aproteinaceous precipitating reagent known as the moist paste method, andwherein the precipitating reagent, in both cases is made by thebase-acid-base hydrolysis of a protein-containing substance.

7 Claims, 1 Drawing Figure FILTER CAKE SQLAR DRY/N6 BEDS ARTIFICIAL H54T DRYER PUL VER/ZER PRDDUC T MINERAL PRO TE/NA TE 0!? NUTRIENT PAIENIEUNov 2 7 m5 I BR/NE SOURCE ORGAN/6 pH CONTROL REA GENT REAGENT l8 FEEDERFEEDER ,2

l6 '1 REACTOR F/L m4 TE CLAR/F/ER 24 FkEsH WAZER r0 DIW F/LTER F/LTRA TEI 26 SOLAR DRY/N6 BEDS ARTIFICIAL I'IEA T DRYER PULVE R/Z E R PRODUC TMINERAL PRO TE INA TE 0/? NUT RIE N T A/ber/ Z. Ric/lords, Jr

INVENTOR.

PRECIPITATION F METAL PROTEKNATES FROM BRINES BY BASE-AClD-BASEHYDROLYSIS This is a continuation-impart application of my earlierapplication Ser. No. 787,147, filed Dec. 26, 1968, now abandoned. I

The present invention relates generally to an improved process for theprecipitation of minerals from brines in the form of metal proteinates,and also in the production of feed grade and agricultural grade metalproteinates by the moist paste method using dry salts as the mineralssource rather than brines, by the utilization of a proteinaceousprecipitating reagent. More particularly, the present invention relatesto an improved process for the preparation of the proteinaceous reagentutilizing base-acid-base hydrolyzation of the proteinaceous rawmaterials.

More specifically, the present invention relates to an improvement inthe method of precipitating minerals from brines as disclosed in U.S.Pat. Nos. 3,374,081 and 3,396,104 to Miller, issued Mar. 19, 1968, andAug. 6, 1968, respectively, the first of which is directed to a methodof obtaining major and trace minerals from brines by the utilization ofproteinaceous precipitating reagents resulting from the enzymaticdegradation of animal manure, sewage, garbage, compost, humus, and fishby-products. As disclosed in said firstMiller patent, two to four weeksare ordinarily required for the production of the proteinaceousprecipitating reagents utilized therein inasmuch as they result from theenzymatic or bacterial degradation of vegetation composts, etc. It willthus be appreciated that the considerable period of time necessary forthe preparation of the proteinaceous precipitating reagent renders theMiller process somewhat uneconomical, and undesirable, for thecontinuous production of feed and fertilizer grade metal proteinates.

The second Miller U.S. Pat. mentioned above (No. 3,396,104) is directedto a similar method of precipitating minerals frombrines but usingproteinaceous precipitating reagents made from raw materials which havebeen pre-treated with ammonia and. phosphoric acid in that sequenceinstead of being produced by the enzymatic degradation method describedin the first U.S. Pat. (No. 3,374,081).

It is a primary object of the present invention to provide an improvedprocess for the precipitation of minerals, in the form of metalproteinates directly from the dry salts of said minerals, as well asfrom natural and synthetic brines to which the Miller patents arelimited,

-by processing the dry salts thereof in the form of a moist pastemixture in the presence of a proteinaceous precipitating reagent derivedfrom the base-acid-base hydrolysis of protein-containing vegetablematter, but using caustic soda and/or caustic potash as the first basetreatment instead of ammonia as specified in Miller US. Pat. No.3,396,104.

Another object of the present invention is to provide an improvedeconomical method of making feed grade metal proteinates and organicplant nutrients by the mixing of dry mineral salts with a base-acid-basehydrolyzed proteinaceous reagent in a mixer-reactor apparatus utilizingonly sufficient water to maintain the aforementioned mixture in a slurryor a moist paste form and wherein the pH necessary for an optimumprecipitation reaction of the metal proteinates is established by theutilization of anhydrous ammonia, lime, or other favorable alkalinesubstances.

A further object of the present invention is to provide an improvedprocess and apparatus system for the treatment of natural saline water,industrial waste brine, synthetic brine, dry salt, for the purpose ofseparating minerals and mineral compounds therefrom in the form of metalproteinates and wherein means are provided for continuously andproportionately admixing a base-acid-base hydrolyzed proteinaceousprecipitating reagent to a continuous flow of an aqueous solution orslurry of a mineral source material followed by adjustment of the pHthereof to provide optimum conditions for the efficient precipitation ofmetal proteinates therefrom which is accomplished in a continuous flowreactor-clarifier where the metal proteinate and- /or complexedorganic-mineral compounds are flocculated, settled and thickened and thesupernatant mineral depleted liquors decanted and disposed of followedby drying of the precipitated material or washing thereof with waterprior to drying to leach out watersoluble components such assodium forexample.

These and other objects of the present invention will be readilyapparent from the following more detailed description of the inventiontaken together with the drawing which comprises a flow diagram of asystem for the continuous production of mineral-proteinate.

When proteinaceous compounds, fibrous vegetation, organic wastesubstances, and decomposition products thereof are utilized as thechelating and/or complexing reagents in the process of the presentinvention, the final products are found to contain metal proteinate,which the Association of American Feed Control Officials defines metalproteinate as, the product resulting from the chelation of a solublesalt with amino acids and/or partially hydrolyzed protein. Briefly, thepresent invention relates to the production of high quality metalproteinates for use in animal feeding and other technical uses byemploying for the chelating or complexing reagent high protein vegetablesubstance such as corn gluten meal, yeast, flour mill by-products, etc.,and non-toxic organic waste products from industry which controlsubstantial amounts of protein, and even including animal manures, aftersubsequent treatment thereof by a base-acid-base hydrolysis. Inaddition, the present invention is suitable for the production oflesser-quality metal proteinates for use in soil fertilization, forexample, by employing for the chelating or complexing reagent anyselected protein-containing substance such as food processing wastes,fibrous vegetation, alfalfa, animal and bird manures, peat, sawdust,tree bark, etc., which material has been subjected to a base-acid-basehydrolysis. The afore discussed hydrolysis of the aforementioned rawprotein-containing material consists of subjecting theprotein-containing raw materials to a strong basic chemical reactionusing caustic soda and/or caustic potash then to a strong acid chemicalreaction using phosphoric acid as the primary I reagent and finally to astrong basic chemical reaction using ammonia or lime. This tripletreatment hydrolyzes certain organic components, i.e., proteins, presentin the raw material and renders the raw material suitable as a chelatingand complexing, i.e., precipitating, reagent. In addition, byutilization of a base-acidbase hydrolyzing procedure proteinaceousprecipitating reagents may be manufactured in a substantially shorterperiod of time than is possible when utilizing enzymatic means for thepreparation of analogous proteinaceous precipitating reagents.Furthermore, of has been found that the preparation of the precipitatingreagents by a base-acid-base hydrolysis produces a reagent that does asuperior job in synthesizing and precipitating the mineral proteinatesand fertilizer minerals from the natural or synthetic brines that arebeing acted upon thereby, and for use in the dry salt paste methoddescribed herein.

The degree of hydrolyzation of the proteins in the raw material is afactor only in quality of the final product as metal proteinates" areofficially defined as products being made from amino acids and/orpartially" hydrolyzed protein.

According to one exemplary mode of carrying forth the present inventionand in order to improve the quantity and efficiency of production ofmetal proteinates, it has been found possible to accomplish the same byutilizing a system schematically illustrated in the drawing wherein itwill be seen that a natural or synthetic brine, slurried dry salt, etc.,indicated as the brine source 10, is continuously fed to a reactorclarifier vessel 12 and wherein proteinaceous precipitating reagent,

prepared by a base-acid-base reaction and stored in an organic reagentvessel 14 is proportionately metered into a flow line 16 connecting thebrine source and the reactor clarifier 12 by feeder means 18 and the pHof the brine-organic reagent flow in the line 16 adjusted by an alkalinereagent, i.e., ammonia and/or lime water supplied from a pH controlreagent vessel 20 and metered into the line 16 by the metering means 22and wherein the pH is adjusted to a value in the order of approximatelypH 8 to pH 10. In this regard, it hasbeen found that the utilization oflime water, preferably made from dolomite lime, rather than theutilization of ammonia for pH adjustment, oftentimes improves theprecipitating action of the proteinaceous precipitating reagent while atthe same time it adds additional magnesium and calcium to the finalmetal proteinate being produced. The controlled pH proteinaceousprecipitating reagent-contacted brine or salt slurry in the ractorclarifier 12 separates into a lower phase comprising the precipitateproduct and an upper phase comprising a waste liquor comprising afiltrate which is decanted off and directed to disposal through conduitpath 24. The precipitate product from the reactor clarifier 12 isdirected to filter means 26 such as comprising a vacuum belt filterwhere a filter cake product is obtained and may, if desired, be washedwith fresh water, for the removal of sodium chloride or other solublesalts which may be present in the filter cake product, after which thefilter cake can be dried by suitable artificial or natural means priorto being pulverized to a fine powder having a density in the order of 45lbs. to 55 lbs. per cubic foot and being only very slowly soluble inwater. It will be understood that the sodium and potassium salts in theoriginal brine-source, being mono-valent, do not efficiently precipitateout, but remain in the supernatant liquor phase in the reactor clarifierand are disposed of with the liquor, and of course with the fresh waterwash utilized to further purify the filter cake product.

When good quality dry salts are used as the raw material mineral sourceit is often desirable to leave all of the ingredients to the reaction inthe final product. Therefore, in this case, no filtration, nor washingof the filter cake will be necessary to remove the water solublesecondary products which have been formed by the reaction of theminerals in the mineral salt used and the proteinaceous precipitatingreagent. Said final, undried, product which is in the form of a wetslurry or undried paste, will go directly to the dryer and thence to thepulverizer, without filtration or washing. Particularly in the casewhere the metal proteinate is to be used as a fertilizer, the solubleingredients which end up in the final product (i.e., ammonium andsulfate radicals, or potassium, etc.) are not objectionableconstitutents, but on the contrary, are valuable soil nutrients.

The following examples are included to more specifically illustrateexemplary means of carrying forth the present invention.

EXAMPLE I 100 pounds of pulverized, or colloidalized, corn gluten meal,60 percent protein, were placed in a closed mixer-reactor and 5 gallonsof fresh water added thereto to form a wet slurry to which 10 pounds ofcaustic potash was added to bring the slurry to a basic reaction ofbetween pH 10 and pH 1 1 after 10 minutes of mixing time. Approximatelyk pint of concentrated sulfuric acid and 3 gallons of percent phosphoricacid was added to the alkaline corn gluten slurry with an attendant heatof reaction whereby the mixture turned to a thick paste having an acidreaction in the range of about pH 1. Asmixing continues for another 10minutes water molecules are consumed in the hydrolyzation of the organicsubstances in the paste mixture and the temperature rises to over 150 Fdue to the chemical reaction involved. To complete the base-acidbasehydrolysis, 15 pounds of anhydrous ammonia was added to the now acidpaste mixture in the mixerreactor but with continued stirring thereof,and the paste mixture was brought back to a strong basic reaction, inthe order of about pH 10 after another 10 minutes mixing time. Thetemperature of the slurry being hydrolyzed usually rises to above 212 Fand steam developed in the closed container but if this does not happenwithin 10 minutes due to extremely cold ingredients additional heat maybe added by an external source if desired. Therefore, within a totalmixing time of 30 minutes from start to finish the hydrolyzed product isready to be used as the primary chelating, i.e., proteinaceousprecipitating, reagent. Processing the precipitating reagent through acolloid mill to further reduce the finished reagent to extremely smallparticle size is sometimes helpful and if desired additional water maybe added to enable the pumping of the finished organic reagent in theform of a slurry into the reactor clarifier 12 from the organic reagentvessel 14. In this particular instance, the brine source vessel 10contained 3,000 gallons of concentrated natural sodium and magnesiumbrine, i.e., bittems from the Great Salt Lake with a density of 29Baume. The afore described reaction product (i.e., from pounds of corngluten meal, caustic potash, phosphoric acid and ammonia) was fed fromthe vessel 14 into the bittems being delivered to the reactor clarifierl2 and the pH of the bittems, when comingled with the organic reagentfeed was adjusted with dolomitic lime water to a pH in the order of 8 to10. The afore described reactants were thoroughly mixed by mechanicalmeans in the reactorclarifier. After settling from an 8 hour detentionperiod the precipitated product in the reactor-clarifier 12 wasapproximately 1,800 pounds of filter cake product was withdrawn from thebottom of the reactor clarifier as measured after filtering. The 1,800pounds of filter cake product was that resulting from concentration ofthe precipitate from the reactor clarifier l2 by-the filter means 26,such as comprising a vacuum belt filter. The washed filter cake productwas then dried by the afore described means to yield only approximately600 pounds of final mineral proteinate product which-was held generallyfree of sodium chloride and contained approximately 12 percent ofmagnesium in the proteinate form together with some calcium and tracesof other poly-valent minerals in about the same ratio amounts as theyappeared in the original bittems. The

final dried product was ground to a fine powder in the pulverizer and ischaracterized by a white color, light and fluffy nature witha density inthe order of 45 lbs. to 55 lbs. per cubic foot, friable to the touch,and only very slowly soluble in water. Furthermore, it was found that byusing lime water made from calcined highmagnesium dolomite limestone asthe pH control means instead of more expensive ammonia, where a littleadditional calcium in the final product is not detrimental, results in adistinct economic advantage.

EXAMPLE II I The method of Example I was repeated, i.e., a proteinaceousprecipitating reagent was prepared from corn gluten as set forth thereinusing the base-acid-base method and wasused as the proteinaceous reagentfor the processing of a synthetic brine formed by dissolvingapproximately 100 pounds of copper sulfate in 100 gallons of water whichreactants were fed to the reactor clarifier 12 wherein the pH wasadjusted to a pH of not over 8 by using a lesser amount of lime water.This degree of alkilinity was found to be an optimum pH for flocculationprecipitation of a copper proteinate. After settling, the supernatantblue liquor was decanted from the reactor clarifier l2 and theprecipitated floc filtered in the means 26, dried with the resultantproduction of approximately 200 pounds of copper proteinate analyzingapproximately 12% copper content.

"TEE 15666365 "sat" forth hereinabo v e has beencar ried forth withiron, zinc, manganese, cobalt, calcium, magnesium, and boron, dependingupon the kind of synthetic brine prepared from commercial chemicals orthe kind of brine obtained from some industrial wastes, such as theferrous sulfate brines being wasted from copper precipitation plants inthe western part of the United States. The proportions of proteinaceousmaterial as well as the type and density of brine being utilized in theproduction of any specific metal proteinate product can be selectivelyadjusted in accordance with the teachings of the present invention asset forth hereinabove to obtain the optimum efficiency and results.

EXAMPLE Ill When low cost commercial dry metal sulfates salts of copper,iron, zinc, manganese, cobalt, magnesium, or

the hydroxides of calcium and dolomite are available as the mineralsource, it is not necessary to completely 1 dissolve these compounds orminerals in large quantities of water to make the quantity of brine thatis represented by natural brines of the sea, or other brine sources,which are generally used for the recovery of magnesium and traceminerals because they contain a goodly percentage of magnesium chlorideand magnesium sulfate. Instead, it has been found that synthesis of feedgrade mineral proteinates, as well as the fertilizer grade mineralproteinates, can just as easily be obtained when using a minimum amountof water in the brine source vessel 10 to slurry or mix into a paste themineral salt or mineral bearing compound prior to adding thebase-acid-base proteinaceous precipitating reagent from the organicreagent vessel 14 thereto. It has been found that the chemical reactionbetween the partially hydrolyzed proteinaceous precipitating reagent andthe inorganic salt or mineral compound, having its pH adjusted by the pHcontrol reagent added from the vessel 20, is just as effective when itconsists of a heavy wet paste condition in the reactor clarifier 12 aswhen the comparable inorganic salt or mineral is thoroughly dissolved inwater such as for the preparation of a brine, and that the final metalproteinate products, without filtering or washing and thus containingall'of the sulfate radical, nitrogen, potassium and phosphorus originalingredients, are in many instances more effective as mineral feed andfertilizer supplements, inasmuch as these additional items are effectivenutrients and are supplemental to the primary metal proteinates whichhave been synthesized in this process. Furthermore, by proportioning theoverall ingredients and by adjustment of the raw materials, thenitrogen, phosphorus and potassium content of the final product can beraised substantially when desired.

Pre-treatment of proteinaceous raw materials by the base-acid-basemethod described herein using caustic potash and/or caustic soda in itsfirst stage to obtain partial hydrolysis of the protein is superior tothe biochemical or enzymatic degradation method and/or to the base-acidpre-treatment method outlined by Miller with ammonia in its first stagetreatment from the standpoint of production economy. This is because ithas been found that the filtering characteristic of the finalprecipitated product, when separating the precipitate from the decantliquor or filtrate, is entirely different when the base-acid-basetreated reagent is utilized as compared with the Miller product.Filtering is very difficult with a precipitate where thefinal basetreatment has been omitted, as in the Miller process. The settling ofthe precipitate and the filtering, washing, and drying of same areprimary factors in the economy of large scale production of high qualitymetal proteinates, and it has been found that by the use of causticpotash and/or caustic soda in the first stage of the pretreatment, andfurther by instituting a third stage in the pre-treatment of theproteinaceous raw material using the ammonia at that point the settlingand particularly the filtering characteristics of the final product canbe improved as much as 500 percent over the Miller method product.

EXAMPLE iv tered through the same size filter paper using the samefunnel and vacuum to a 60 percent moisture cake specimen. On aproduction scale the presently described process is superior to theMiller process from an economic standpoint because the size and capacityof the process filtering equipment can be reduced by 500 percent whenusing the process described herein.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the an, it is not desired to limit theinvention to the exact method, operation and product shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

I claim:

1. In a method of obtaining feed and fertilizer grade organic mineralcomplexes, known as metal proteinates, by reacting a proteinaceousprecipitating reagent and a mineral source material selected from thegroup consisting of natural brines, bitterns, synthetic brines, and drymineral salts to form said organic mineral complexes in the nature of aprecipitate, the improvement comprising:

a. preparing said reagent by the base-acid-base hydrolysis of a proteincontaining substance selected from the group consisting of vegetablematter, vegetable matter degradation products and mixtures thereof; and

b. admixing said reagent and said mineral source material and adjustingthe pH of the resulting mixture to the range iito 1Q whe eby saidreagent and said material source react to 5511 said organic mineralcomplex precipitate.

2. A method, as claimed in claim 1, wherein said proteinaceousprecipitating reagent and said mineral source material are admixed toform an aqueous slurry and further including the step of separating theprecipious slurry-of said protein containing substance, adjusting the pHof said slurry with a base selected from causlate from the aqueous phaseof said slurry.

3. A method, as claimed in claim 1, wherein said mineral source materialis a dry mineral salt and said proteinaceous precipitating reagent andsaid mineral source material are admixed to form an aqueous moist pastemixture, whereby said organic mineral complexes are formed in said moistpaste which also contains all of the associated ingredient elements ofthe reaction.

4. A method, as claimed in claim 1, wherein the pH of said mixture isadjusted by addition thereto of a base selected from the groupconsisting of ammonia and lime water.

5. A method, as claimed in claim 1, wherein said base-acid-basehydrolysis comprises forming an aqueous slurry of said proteincontaining substance, adjusting the pH of said slurry with a base to therange 10 to l l; adjusting the pH of the resulting slurry to about 1with an acid, and, adjusting the pH of the base-acid treated slurry toabout 10 with a base.

6. A method, as claimed in claim 1, wherein said base-acid-basehydrolysis comprises forming an aquetic soda and caustic potash to therange 10 to l 1; adjusting the pH of the resulting slurry to about 1with an acid selected from phosphoric acid, sulfuric acid and mixturesthereof; and, adjusting the pH of the base-acid treated slurry to about10 with a base selected from ammonia and lime water.

7. A method, as claimed in claim 6, wherein said base-acid-basehydrolysis comprises forming an aqueous slurry of said proteincontaining substance; adjusting the pH of said slurry with causticpotash to pH 10-11; adjusting the pH of the resulting slurry with amixture of sulfuric and phosphoric acids to a pH of about I andadjusting the pH of the base-acid treated slurry with ammonia to a pH ofabout 10.

2. A method, as claimed in claim 1, wherein said proteinaceousprecipitating reagent and said mineral source materiaL are admixed toform an aqueous slurry and further including the step of separating theprecipitate from the aqueous phase of said slurry.
 3. A method, asclaimed in claim 1, wherein said mineral source material is a drymineral salt and said proteinaceous precipitating reagent and saidmineral source material are admixed to form an aqueous moist pastemixture, whereby said organic mineral complexes are formed in said moistpaste which also contains all of the associated ingredient elements ofthe reaction.
 4. A method, as claimed in claim 1, wherein the pH of saidmixture is adjusted by addition thereto of a base selected from thegroup consisting of ammonia and lime water.
 5. A method, as claimed inclaim 1, wherein said base-acid-base hydrolysis comprises forming anaqueous slurry of said protein containing substance, adjusting the pH ofsaid slurry with a base to the range 10 to 11; adjusting the pH of theresulting slurry to about 1 with an acid, and, adjusting the pH of thebase-acid treated slurry to about 10 with a base.
 6. A method, asclaimed in claim 1, wherein said base-acid-base hydrolysis comprisesforming an aqueous slurry of said protein containing substance,adjusting the pH of said slurry with a base selected from caustic sodaand caustic potash to the range 10 to 11; adjusting the pH of theresulting slurry to about 1 with an acid selected from phosphoric acid,sulfuric acid and mixtures thereof; and, adjusting the pH of thebase-acid treated slurry to about 10 with a base selected from ammoniaand lime water.
 7. A method, as claimed in claim 6, wherein saidbase-acid-base hydrolysis comprises forming an aqueous slurry of saidprotein containing substance; adjusting the pH of said slurry withcaustic potash to pH 10-11; adjusting the pH of the resulting slurrywith a mixture of sulfuric and phosphoric acids to a pH of about 1; andadjusting the pH of the base-acid treated slurry with ammonia to a pH ofabout 10.